Selecting Quests in a Party

Why can I not select a quest when in a party so everyone sees it? It's frustrating trying to describe where we are going and what the mission objectives are.

Either make sure that both players have the quest, or that both of you have the same quest highlighted in your quest log (that way you'll both get the same green arrow).
If your partner is just helping you (has already completed/can't get/doesn't want that quest) they'll just have to follow you. The directional indicator will not show up on their map.

Taphoo